Apparatus for drawing ellipses



Oct. 26, 1954 F. M. STANLEY 2,692,432

APPARATUS FOR DRAWING ELLIPSES AFiled Deo. 1l, 1951 5 Sheets-Sheet l L ti O IN V EN TOR. FL @Rines/1s TAN L1: Y.

Oct. 26, 1954 F. M. STANLEY APPARATUS FOR DRAWING ELLIPSES 5 Sheets-Sheet 2 Filed DeC. 1l, 1951 IN V EN TOR. FLonE/vcE/IJTANLEM Oct. 26, 1954 F. M. STANLEY APPARATUS PoR DRAWING ELLIPSES 5 Sheets-Sheet 3 Filed Dec. ll, 1951 INVENTOR. F'LORENCES TANLE Y.

BY A y Oct. 26, 1954 F. M. STANLEY APPARATUS FOR DRAWING ELLIPSES 5 Sheets-Sheet 4 Filed Dec. ll

INVENTOR. FL OHENCEMSTANLE Y.

Oct. 26, 1954 F. M. STANLEY APPARATUS FOR DRAWING ELLIPSES 5 Sheets-Sheet 5 Filed Dec.

V'. R mM m7 V5 mm E 4 m E m Fw Patented Oct. 26, 1954 UNITED STATES PATENT OFFICE APPARATUSv FOR DRAWING ELLIPSES Florence M. Stanley, Dayton, Ohio Application December 11, 1951, Serial No. 261,113

3 Claims. l

This invention relates to a method and apparatus for drawing ellipses, although not necessarily so limited, in that the method and apparatus may be used for drawing various arcs and combinations thereof.

The problem of preparing drawings of round objects, such as wheels, tubing, gears, drums, and the like, in perspective involves much tedious work. The use of ellipticaI templates simplifies this work considerably, but the number of templates required for drafting work wherein ellipses of many different sizes must be drawn from time to time is so great that it is impractical to rely on the use of such templates. Furthermore, a separate set of templates would be required for every different type of perspective. Thus, a 45 perspective would require one set of templates, whereas a 30 perspective would require an entirely different set of templates.

Various short cuts have been proposed from time to time for simplifying the construction of ellipses, but at the best these have involved a large amount of construction work. It is an object of this invention to provide an improved method and apparatus for use by draftsmen in preparing ellipses.

More particularly, it is an object of this invention to provide a simple method and apparatus which may be used for constructing ellipses of all sizes.

Another object of this invention is to provide a simple device which may be used for constructing ellipses of all sizes and at many diierent angles.

Other objects and advantages reside in the construction of parts, the combination thereof and the mode of operation, as will become more apparent from the following description.

In the drawings:

Figure 1 is a plan view of a device for use in drawing ellipses used in axonometric or oneplane projection by four different methods, namely, the Stevens method, the approximate fourcentered ellipse method, the true ellipse method, and the four-center ellipse method, and shows the actuators set to draw a 30 isometric ellipse by the approximate four-centered ellipse method;

Figure 2 is a plan view of a similar device for use in axonometric or one-plane projection of ellipses by the four-center ellipse method, size of rhombus only given, and showing the actuators set to draw a 30 four-center ellipse in a two inch rhombus;

Figure 3 is a plan view of a somewhat similar device for Orthographie projection of ellipses in 2 which the actuators are shown set for drawing a 30 approximate four-centered ellipse;

Figure 4 is a plan View of a device which may be used for both aXonometric and Orthographie projection in which only two actuators have been provided, whereby the device may be used in those cases Where the minor diameter is not given, the actuators being set for a 30 true ellipse for Orthographie projection;

Figure 5 is a plan View of a multi-ellipse graph for use in drawing 30 isometric ellipses in axonometric and oblique projection by use of the four-center ellipse method; and

Figure 6 is a fragmentary sectional view taken substantially on the line 6 6 of Figure 4.

Referring now to the drawings wherein there are shown several different types of devices for use in constructing ellipses of various shapes and sizes, each of the devices consists of a graph or chart in which there is provided a iirst series of vertically arranged lines which represent the major diameters of ellipses of different sizes and a second series of intersecting lines which pass through the zero point on the chart and which measure off on the first series of lines the various radii to be used in constructing ellipses. The various devices shown in Figures 1 through 6 may be sold as a set or individually.

It will be noted that on the face of each one of these charts there appear a certain number of illustrations and instructions for the guidance of those using the charts. While these instructions are self-explanatory and adequately serve to instruct those skilled in the art how to use the devices, a brief further description will here be given.

For. convenience of description, all like or corresponding parts have been designated by the same reference numeral in each of the Figures of the drawings. The construction shown in Figure 1 is illustrative of the constructions shown in Figures l through 4 and therefore will be described in detail. Reference numeral 20 in each instance designates a flat plate-like chart element which may be made of plastic, cardboard, or any other suitable material and serves to pivotally support the actuators 22, 24 and 26. Each of these actuators is supported for rotation about a xed pivot point 28 located at the zero point of the chart. These actuators are preferably made of transparent plastic, so as not to obscure the printed scale lines and other indicia which are provided directly on the chart 20.

As shown, the element 20 has printed thereon a iirst set of evenly spaced vertical lines 30 which stand for or represent the lengths of the major diameters of the ellipses to be drawn. Similar lines are provided on each of the other charts shown herein and in each case, except in Figure 2, these lines stand for the lengths of the major diameters of the ellipses to be drawn, whereas in Figure 2 the corresponding lines stand for the size of the rhombus used in constructing fourcenter ellipses.

A second set of vertical lines 42 are provided in the devices shown in Figures 1 through 4 on which are marked the points at which lines on the movable actuators, such as the actuators 22, 24, 28 and 31, should be set for any given type of ellipse, as will be explained more fully hereinafter. A third set of arcuate lines d3 is also provided, on each line of which is indicated the particular points at which each particular actuator is to be set for drawing the various types and degrees of ellipses listed below the base line A-B.

The actuators 22, 24 and 26 are provided with lines 32, 34 and 3S respectively which extend from the pivot point 28 which is the zero point of the chart to the extreme end of the actuators. It will also be noted that these actuators have printed thereon the letters F, E and C respec tively at their outer ends for a purpose to be explained hereinafter.

These actuators have been shown in Figure l as being set to draw the 30 ellipses similar to the 30 ellipse designated by the reference numeral 40 and appearing directly on the front face of the chart 20. Thus, the liney 3S on the actuator 26, which has the letter C printed on it, has been set to intersect the line 42, which designates this type of ellipse, at the point on the line marked bythe letter C. The distance from the line AB (the base line coinciding with the X axis of the chart) to the line C on the actuator 26 for a 2 ellipse is used for determining the length of thev line B C shown in the ellipse 40. The actuator 24 (marked with the letter E) hasbeenset to coincide with the mark E on the applicable line 42, and the actuator 22 (marked with the letter F) has been set to intersect. the same line 42 at the point marked by the letter F. In other words, when it is determined what type of ellipse is to be drawn and when it is determined at which, angle the ellipse is to be shown, thev actuators designated by the letters C, E and F are set at the points designated by the letters C, El. andF on the particular line 42 which represents that particular ellipse. It should be noted that the actuators C, E and F remain in the same position for similar ellipses of different sizes.

It will alsoY be noted that in the embodiment of the invention shown in Figure 1 there is a xed line designated by the letter D. The reason for this line being fixed in this particular device rather than being mounted on a movable actuator as in Figure 2 is that the distance from the X axis or the line AB to the line D is the same in all types of ellipses of a given diameter. rI'he distances measured below the line D represent the distances for constructing the arcs along the major axis, While above the line D they are used for locating the centers of the arcs along the minor axis. The line D is therefore called a major and minor axis differentiating line.

The various radii which are required for use in drawing an ellipse like the ellipse 40 illustrated on the chart may be found or may be stepped oi by dividers from the chart. Thus,

the radii are obtained by measuring distances along the vertical line corresponding to the major diameter of the desired ellipse, the radii CD is obtained by measuring the distance from the line C (on the actuator 26) to the line D, and the distance DE is the distance from the line D to the line E(34) on the actuator FM4).

As pointed out hereinabove, the numersals 1, 2 and 3 appearing below the -X axis or the line AB stand for lengths of major diameters of the ellipses to be drawn, except in Figure 2 Where these stand for the size of the rhombus as used in constructing the four-center ellipses as explained hereinabove. The multi-ellipse graphs shown furnish a. means by which an ellipse may be drawn by a short cut method in any size, degree, and conventional method desired and for either axonometric and oblique projection or for Orthographie projection.

For simplicity, reference is made to the chart in Figure 5, from which the ellipse shown on the chart 20 is constructed. The majoraxis of this ellipse is 2 and inch long, and the radiifor` drawing it are found on the Vertical line erected at 2 and 1-5.; at line AB. It isnoted that the distances Bg and C D on the 2 and e line are actually equal to half of the major axis, and thatl the arc constructed at the extremity ofthe major axis which forms portions of the ellipse is drawn with a radius of Q D. In other words, from the` intersection of the lines C, D, E and F with thev 2 and line the distance B C from the chart is laid off along the major axis of the ellipse to be drawn on either side of the minor axis. these points as centers and the distance gl) as a radius, arcs are struck at the extremities of the major axis. In order to complete the ellipse, it is necessary to draw arcs at the extremitiesv of the minor axis. This is accomplished by laying of the distances lll and gli' along the minor axis. With this point as a center, an arc is constructed so as to be tangent to the rst constructed arcs. It is noted that the center' for this arc is located on one side of the major axisl and the arc is located on the other side of the major axis. In order to complete the ellipse the distances on the chart DE and EF are laid off along the minor axis in a direction opposite' to the other side arc according to the same method just described. The only difference between Fig'- ure 5 and the other ngures is thatv Figure 5 does. not use actuators since it sets forth only one type of ellipse, i. e., the four-center isometric ellipse, while the other gures require two to fouractuators to accommodate the diierent methods and angularities of the ellipses..

In Figure 1 an ellipse is shown at 40. In constructing this ellipse the major axisis in a horizontal plane merely to demonstrate the mechanical construction of the ellipse. It is noted that the major diameter would be more apt to be in any other position than in a horizontal plane. In other words, if one were going to draw an ellipse having its major axis at a slant of 30 from the vertical and the minor axis at right angles `with it, one need only refer to the chart to determine the centers for striking the necessary arcs to complete the ellipse. to construct the ellipse shown at 40 which is a 30 ellipse having a two inch major diameter, the actuators 22, 24 and 26 are placed upon the proper marking on the line shown at 42. The distances for constructing the ellipse are found on the line. shown at 44. The distance Bg is For example,v

laid oif on the major axis in both directions from the center O, locating the centers of the arcs to be constructed at G and G. With these points as center, the distance l@ from the chart is then laid off on the major axis with the centers at G and G and the arcs struck off at the extremities of the major axis. To complete the ellipse the distances D El and E F are laid off along each side of the minor axis from the center O'. The distance DE is shown by the letters `M and N. The points on the minor axis for locating the centers of the arcs are found by laying off the distance1 from M and N. This establishes the centers H and H. With H and H as the centers, the arcs are struck tangent to the rst two arcs to complete the ellipse. It is noted that the center for striking the arc is on one side of ther` major axis and the arc is on the other side of the major axis. The radius R is equal to the distance E plus E ig for the particular ellipse.

It should be understood that the measurements laid olf on the vertical line at 2 are determined by intersection with that line of the lines C, D, E and F on the adjustable actuators, beginning at its lower end which rests on line AB and progressing upwardly in the following order-C, D, E and F. Since plus C D represents one-half the major diameter, hence lli) is constant for all ellipses constructed with the device shown in Figure 1. Therefore, D does not need an actuator but is drawn in ink on the graph shown in Figure 1. Consequently, only three actuators are needed here. This cannot be said about the graph shown in Figure 2, however, since the points D are not constant with each other and therefore require an adjustable actuator 31 which may be set for the particular type of ellipse to be drawn. In the device shown in Figure 4, there are only two actuators necessary, since this device is intended to be used for drawing ellipses where the minor diameter is not given and in which an actuator corresponding to actuator 22 of Figure l would not be required.

The multi-ellipse graph shown in Figure 5 of the drawings needs no actuators, since it shows the measurements for only a 30 isometric ellipse. Similar graphs would be necessary for other degrees. Figure 5 is the only full scale drawing herein presented and consequently it was possible to divide the line AB into thirty-seconds of an inch. The graph shown in Figure 5 is preferable from the standpoint of simplicity, but it is obvious that a large number of these graphs would be required for drawing different types of ellipses, due to the fact that the lines designated by the letters C, D, E and F are not adjustable.

In each of the devices utilizing adjustable actuators which are pivotally mounted at the zero point of the graph, one would prefer to provide some means for clamping the actuators into a given adjusted position While one is taking oi the measurements for constructing a particular ellipse. Figure 6 shows one form of clamping device which may be used in each of the charts shown in Figures 1, 2, 3 and 4. Thus, a screw 50, which is carried by the member 20, serves as a pivot for the actuators 24 and 26 shown therein, as well as any additional actuators one might use. A thumb nut 52 cooperates with the screw 50 so as to firmly clamp the actuators between the washer 54 and the member 2D.

Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

Having thus described my invention, I claim:

l. In an ellipse forming chart, comprising a base member, a horizontal base line having one end at the zero point on the chart, a rst series of ordinate lines equally spaced on said base member according to the inch scale and starting at said zero point, a major and minor axis differentiating line on said base member passing through said zero point and overlying said rst series of lines, a plurality of actuators each having a line thereon that passes through the zero point on said chart and overlies said first series of lines, the actuators being pivotally mounted at the zero point on said chart, means on said base member for indicating the correct position of said actuators according to the desired e1- lipse to be drawn, distances on said rst series of lines between said differentiating line and said base line providing the length of the major axis, distances between the differentiating line and one of said actuator lines providing the length of the radius of the arcs to be drawn on the major axis, and distances above said differentiating line between the other actuator line and said differentiating line providing the distances for locating the centers of the arcs at the extremities of the minor axis.

2. In an ellipse forming chart comprising a base member, a horizontal base line having one end at the zero point on the chart, a first series of ordinate lines equally spaced on said base member according to the inch scale and starting at said zero point, a major and minor axis differentiating line on said base member passing through said zero point and overlying said first series of lines, a plurality of actuators each having a line thereon that passes through the zero point on said chart and overlies said first series of lines, the actuators being pivotally mounted at the zero point on said chart, another series of ordinate lines on the base member being spacedly positioned according to the angle at which the ellipse is to be drawn, means on said other series of ordinate lines for indicating the correct position of the lines on the actuators according to the desired ellipse to be drawn, distances on said rst series of lines between said differentiating line and said base line providing the length of the major axis, distances between the differentiating line and one of said actuator lines providing the length of the radius of the arcs to be drawn on the major axis, and distances above said differentiating line between the other actuator lines and said diiferentiating line providing the distances for locating the centers of the arcs at the extremities of the minor axis.

3. In an ellipse forming chart comprising a base member, a horizontal base line having one end at the zero point on the chart, a rst series of ordinate lines equally spaced on said base member according to the inch scale and starting at said zero point, an actuator having a major and minor axis differentiating line thereon, the actuator being pivotally mounted at the zero point on the chart and overlying said iirst series of lines, a plurality of actuators each having a line thereon that passes through the zero point on said chart and overlies said first series of lines, the actuators being pivotally mounted at the zero point onk said chart, another seriesof ordinate lines on the basen member spacedly positioned accordingy to the angle at which the e1- lips'eis to be drawn, means on said other series of ordinate lines for indicating the correctl position of the lines onthe actuators according to the desired ellipse to be drawn, distances on said first series of lines between said differentiating line and said hasev line providing the length of the major axis, distances between the dinerentiating line and one of said actuator lines providing the length ofthe radius of the arcs to be drawn on the major axis, and distances above said differentiating line between the other actuator lines and said differentiating line providing the distances for locating the centers of the arcs'at the extremities of the minor axis.

References Citedv inA theI le: of this patentl Number 'Number UNITED STATES PATENTS Name Date Zahm Dec. 31 19181 Zona May. 27, 1919 Brinkman Apr.r10, 1928i Wolfe Feb. 1'0, 1942i McGuckin Mar. 8', 1949 FOREIGN PA'IENTSA Country Date Germany Sept. 12, 1887i Great Britain 1911. Great Britain Apr. 27, 1922; 

